AJP - Cell Physiology, Vol 254, Issue 6 C847-C854, Copyright © 1988 by American Physiological Society
Ouabain-resistant, amiloride-sensitive Na+-K+ pumping activity and morphological changes are inducible
J. A. Epstein and C. Lechene
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
The functional expression of a ouabain-resistance gene has been studied in
a transfected cell line, OR-6 cells. These cells possess a
ouabain-inhibitable, amiloride-resistant Na+-K+ pump under control
conditions. They can be induced by brief culture in the presence of low
concentrations of ouabain to express a ouabain-resistant,
amiloride-sensitive Na+-K+ pumping activity. They revert to the uninduced
phenotype shortly after removal of ouabain from the culture medium. When
placed in low-potassium, low-serum, or dibutyryl adenosine 3'-5'-cyclic
monophosphate-containing media, these cells produce long cellular
extensions. Thus a single inducible gene appears to regulate sensitivity of
the Na+-K+ pumping activity to cardiac glycosides and to amiloride, and it
may be related to important characteristics of cellular morphology.
